Safety pawl



July 11,, 1933)., n H H BARBER 1,917,215

SAFETY PAWL Filed Oct. 15, 1930 2 Sheets-Sheet 74C Az7 g5 July 11, 1933. H. H. BARBER 1,917,215

SAFETY PAWL Filed Oct. 15, 1950 2 Sheets-Sheet 2 flgg Patented July 11, 1933 ST TES HARRY PLBAREEB, OF AURORA, ILLINOIS, ASSIGNOR TO BARBER GREENE COMFANY, OF

7 AURORA, ILLINOIS, A CORPORATION OF ILLINOIS SAFETY PAWL Application filed. October 15, 1930. Serial No. 488,765.

This invention relates to a safety pawl adapted for use in connection with conveyors but susceptible of other similar uses.

The invention comprises the, novel structure and combination of parts'hereinafter described and more particularly pointed out and defined in the appended claims.

In the accompanying drawings which illustrate a preferred form of this invention and in which similar reference numerals refer to similar features in the different views:

Figure l is a fragmentary side elevational view of the upper portion of a conveyor boom illustrating the application of the safety pawl thereto.

Figure 2 is an enlarged sectional View taken through the safety pawl housing illustrating parts broken away and parts in elevation.

Figure 3 is an enlarged end elevational view of the conveyor boom illustrating the attachment of the safety pawl housin Figure 4 is an enlarged sectional view taken upon the line TVIV of Figure 2.

Referring to the drawings, there is shown the head shaft 1 mounted upon the upper end of the conveyor boom. A ratchet wheel 2 is keyed upon this shaft andis enclosed by a casing consisting of a peripheral member 5 having a groove 6 for receiving the toothed portion of the ratchet wheel and having flanges 4 for frictionally engaging with contacting flanges 3 upon the ratchet wheel 2. Side plates 7 8 are bolted to the sides of the peripheral member 5 for forming an enclosed casing for the ratchet wheel. A pawl 9 is adapted for engagement with the ratchet wheel 2 and this pawl is mounted intermediate its end upon a shaft 10 which is sup ported by the side walls 7 and 8 of the casing. The outer end of the pawl 9 is connected to one end of a link 11. which is pivoted at its other end to the frame of the conveyor boom, as indicated at 12.

Referring to Figure 2, it will also be noted that a stop member 14 extends between the two side plates 7 and 8 for limiting the outward movement of the safety pawl 9, as will hereinafter more fully appear.

It will be obvious that when the conveyor including its chains 16, that is intended to be supported upon the boom rotates with its upper flight traveling in an upward direction, the ratchet wheel 2 will rotate in a clockwise direction and through the friction engendered between the flanges 3 and 4:, the housing will tend to rotate in a clockwise direction and swing or tend to hold the pawl 9 out of engagement with the ratchet wheel 2.

However, should the conveyor chains for some reason tend to rotate in a reverse direction, the ratchet wheel willalso rotate in such a reverse or anti-clockwise rotation and cause the housing to rotate in a counterclockwise direction, with the result that the pawl 9 will be swung into engagement with the ratchet wheel 2 and immediately stop such reverse rotation of the ratchet wheel and the conveyor which is controlled thereby. This swinging movement of the pawl 9 is due to the fact that it is connected to the conveyor boom by a link 11 and is bound to swing during the rotation of the housing which is in frictional engagementwith the ratchet wheel that is keyed upon the shaft. The conveyor isadapted to be driven by a driving chain 17.

I am aware that many changes may be made, and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon, otherwise than necessitated by the prior art.

I claim as my invention:

1. The combination with a rotatable shaft, a ratchet wheel keyed upon said shaft, a housing surrounding said ratchet wheel for relative rotation, said housing and ratchet wheel having contacting flanges for frictional engagement, a pawl pivoted to said housing, a support and a link connecting said support with said pawl whereby rotational movement of said housing will swing said pawl for the purpose set forth.

2. The combination with a rotatable shaft, a ratchet wheel keyed upon said shaft, said ratchet wheel having laterally extending flanges, a peripheral housin member having, flanges in frictional engagement with the flanges on said ratchet, a pawl pivoted upon said peripheral member and adapted for engaging said ratchet wheel, a support and a link connecting said pawl and support whereby rotational movement of said housing will swing said pawl into and out of engagement with said ratchet wheel.

In testimony whereof I have hereunto subscribed my name Aurora, Kane County, Illinois.

HARRY H. BARBER. 

